freeCodeCamp/curriculum/challenges/chinese/03-front-end-libraries/jquery/change-the-css-of-an-element-using-jquery.md

---
id: bad87fee1348bd9aed908826
required:
  - link: 'https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.2.0/animate.css'
challengeType: 6
forumTopicId: 16776
title: 使用 jQuery 更改元素的 CSS
---

## Description
<section id='description'>
我们也能用 jQuery 直接改变 HTML 标签的 CSS。
jQuery 有一个<code>.css()</code>方法，其能改变标签的 CSS。
下面的代码效果是把颜色变蓝：
<code>$("#target1").css("color", "blue");</code>
这与通常的 CSS 声明略有不同，因为这个 CSS 属性和它的值在英文引号里，并且它们用逗号而不是冒号间隔开。
删除你的jQuery选择器，并留下空的<code>document ready function</code>。
请选择<code>target1</code>并将其颜色变为红色（red）。
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>target1</code>标签应该有红色文本。
    testString: assert($("#target1").css("color") === 'rgb(255, 0, 0)');
  - text: 仅用 jQuery 给标签添加类。
    testString: assert(!code.match(/class.*animated/g));

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='html-seed'>

```html
<script>
  $(document).ready(function() {
    $("button").addClass("animated bounce");
    $(".well").addClass("animated shake");
    $("#target3").addClass("animated fadeOut");
    $("button").removeClass("btn-default");

  });
</script>

<!-- 请修改本行以上的代码 -->

<div class="container-fluid">
  <h3 class="text-primary text-center">jQuery Playground</h3>
  <div class="row">
    <div class="col-xs-6">
      <h4>#left-well</h4>
      <div class="well" id="left-well">
        <button class="btn btn-default target" id="target1">#target1</button>
        <button class="btn btn-default target" id="target2">#target2</button>
        <button class="btn btn-default target" id="target3">#target3</button>
      </div>
    </div>
    <div class="col-xs-6">
      <h4>#right-well</h4>
      <div class="well" id="right-well">
        <button class="btn btn-default target" id="target4">#target4</button>
        <button class="btn btn-default target" id="target5">#target5</button>
        <button class="btn btn-default target" id="target6">#target6</button>
      </div>
    </div>
  </div>
</div>
```

</div>



</section>

## Solution
<section id='solution'>

```html
<script>
  $(document).ready(function() {
    $("button").addClass("animated bounce");
    $(".well").addClass("animated shake");
    $("#target3").addClass("animated fadeOut");
    $("button").removeClass("btn-default");
    $("#target1").css("color", "red");
  });
</script>

<!-- Only change code above this line. -->
<div class="container-fluid">
  <h3 class="text-primary text-center">jQuery Playground</h3>
  <div class="row">
    <div class="col-xs-6">
      <h4>#left-well</h4>
      <div class="well" id="left-well">
        <button class="btn btn-default target" id="target1">#target1</button>
        <button class="btn btn-default target" id="target2">#target2</button>
        <button class="btn btn-default target" id="target3">#target3</button>
      </div>
    </div>
    <div class="col-xs-6">
      <h4>#right-well</h4>
      <div class="well" id="right-well">
        <button class="btn btn-default target" id="target4">#target4</button>
        <button class="btn btn-default target" id="target5">#target5</button>
        <button class="btn btn-default target" id="target6">#target6</button>
      </div>
    </div>
  </div>
</div>
```

</section>